Network security on a computer network includes provisions made as part of the computer network's security policies. The security policies are most often under the control of a person or group of people, such as a network security administrator or administrators, who are responsible for the network security. The security policies are intended to protect the computer network, including one or more network-accessible resources, from unauthorized access.
Network security often begins with the authentication of all users who are attempting to access the computer network. Once authenticated, various mechanisms are used to enforce access policies, such as determining what services or resources available on the computer network are allowed to be accessed by the particular user having been authenticated by the network security. Network security may also include various audit functions intended to monitor the computer system for such things as un-authorized access to the computer network, un-authorized access to one or more of the resources of the computer network by an authenticated user, or improper use of one or more resources of the computer network by anyone accessing the computer network.